1. Field of the Invention
The present invention relates generally to positioning systems and methods. More particularly, the present invention provides person or object positioning in a predetermined area.
2. Background of the Invention and Related Art
The ability to ascertain the location of an individual or object occurs in countless scenarios. One such scenario includes emergency situations where an emergency worker is in a building wherein potential danger lies. An example of this is a firefighter fighting a fire inside a burning building. It would be very beneficial and potentially life saving to be able to track the movements and current location of a firefighter inside a burning building. Also, it would be very advantageous to be able to transmit information relating to the person whose location is being tracked and surrounding environment which surrounds them. This would be an example of a scenario wherein the locating area varies.
In the firefighter example, the location would vary depending on where the fire may be located. However, in numerous positioning embodiments the objects or persons whose position is to be determined are located in a fixed area for at least a given period of time. In this scenario the object or person may be moving within a given defined area and its/their position is desired to be located. An example of this may include tracking a prison guard inside of a prison. Danger is inherent in a prison environment and knowing where prison guards are within the confines of a prison is vital. An additional benefit would be to not only be able to know the location of a prison guard, but also to enable the prison guard to communicate on the same device that is tracking his location. Furthermore, the ability to provide an emergency notification would be beneficial. Consequently, if one mobile unit could provide communication, alerting and positioning, the benefits to prison guards would be enormous.
Another example of a person or object moving within a defined area is a child in a theme park such as Disney World in Orlando, Fla. This environment typically includes family members with children. Hundreds of children are lost in Disney World each year as children wander off if the parents turn their head for even a brief period. This can be a very dangerous situation and there is an immense need to be able to find the lost child's exact position immediately. With thousands of people and a large geographic area, this is a difficult task.
Another important task is to know the position of items in a warehouse. Billions of dollars are spent each year on shipping items from one location to another. Many times these items are stored in several locations prior to its arrival at the final destination. In a prior application, filed by the present inventor, application Ser. No. 09/407,106, filed Sep. 27, 1999, entitled “System and Method for Monitoring Assets, Objects, People and Animals Utilizing Impulse Radio”, now U.S. Pat. No. 6,512,455, issued Jan. 28, 2003, a method of tracking such items utilizing impulse radio was described and is incorporated herein by reference. However, positioning architectures in that application were not used to determine the exact location of items within a warehouse or other area.
Further, numerous other techniques, both completely wireless and partially non-wireless, have been attempted for position locating with limited success. The reason for this limited success is the inherent RF properties of existing technologies. In the burning building example, severe multipath problems exist as well as an extremely noisy RF environment is present. The RF environment is cluttered with emergency radio signals from police and firemen as well as hand held radios from firemen working on the fire. Most buildings are filled with multipath propagation problems and are inherently unreliable in that environment; and a fireman in a burning building is a situation that requires extreme reliability.
In areas such as the Disney World example, attempts have been made to be able to locate people and objects, but again with limited success. The metal rides, the large buildings and many other multipath causing things are present. Thus, a child may be in between two large buildings and under a metal picnic table, cowering in fear for having lost his parents, and conventional radios may not be able to find his position. Further, power and component requirements for conventional wireless technology make placing transmitters with each child problematic due to the size, expense and limited battery life of the transmitters. Therefore, there is a strong need for a wireless position locating system that has advantageous multipath propagation properties, has low transmit power and can be mobile if needed. Also, there is a need for a wireless locating system that, due to it's inherent properties, can be implemented with a large number of varying architectures.